In the case of a display device displaying video by obliquely transmitting light to a screen, a method of projecting an image on which trapezoidal distortion correction is executed previously by image processing is generally used to reduce occurrence of trapezoidal distortion. For example, Patent Literature 1 discloses a method of maintaining uniformity of pixel arrangement by controlling a method of driving a uniaxial or biaxial swinging mirror and optically executing the trapezoidal distortion correction on the screen, in a display device that scans a laser beam by the swinging mirror and executes drawing.